The number of electronic services which are offered by service providers to customers has grown enormously. These electronic services include communication services (e.g. email), information services (e.g. providing news, legal information, financial information etc) and media services (e.g. providing videos, music etc). Service Oriented Architectures (SOAs) are typically used to provide these services and SOAs use distributed systems and collections of loosely coupled services to provide the required functionality in a manner which improves flexibility and adaptability.
When a customer subscribes to a service, the agreement between the parties is generally described in a service contract and one aspect of this contract is a service level agreement (SLA). An SLA describes what the service offers and under which conditions the service is offered, such as the price and includes an expected quality of the service. Problems may arise where the SLA is ambiguous and therefore SLA languages have been developed which are intended to remove ambiguities about what guarantees are provided and how data is collected and analyzed to confirm whether the guarantees are being met. Failing to meet guarantees can have serious consequences which may include financial penalties and therefore it is important that the services are monitored correctly and accurately against the relevant SLA.
The embodiments described below are not limited to implementations which solve any or all of the disadvantages of known SLA infrastructures and SLA languages.